This proposal is to produce a rapid serodiagnostic and accurate confirmatory test for detection of Trypanosoma cruzi infections built on a novel recombinant antigen. This parasite, transmitted via blood transfusion, is prevalent in Latin America, and the causative agent for fatal Chagas' disease. Positive blood donors have been identified, and transmission via the insect vector has been reported in the U.S.A. Current methods to detect infection involve serological screening using whole parasites, or crude lysates, and confirmation tests in the U.S.A use a complex radioimmunoprecipitation assay. In this proposal we will incorporate a novel recombinant protein TcF that contains four different repeating epitopes with additional known antigens or novel antigens to be identified by serological expression cloning using low titer/RIPA confirmed and TcF low or non-reactive sera from U.S.A. blood donors and from different regions of Central America. This proposal details (1) the development of a rapid, inexpensive test for the diagnosis of T.cruzi infections in small clinics/blood banks in Latin America and (2) a confirmatory assay for use in the U.S.A in diagnosing T. cruzi infections in prospective U.S.A. cardiac surgery patients with high risk factors for Chagas' disease. These studies will exploit the expertise of InBios to develop rapid tests in combination with Corixa TcF antigen. The studies will also benefit from a close collaboration with renowned consultants and collaborators as well as access to their serum banks.